The term â€˜Modern Methods of Constructionâ€™ (MMC) Â embraces a range of technologies involving various forms Â of prefabrication and off-site assembly.
MMC is increasingly regarded as a realistic means of Â improving quality, reducing time spent on-site, improving Â on-site safety and addressing skills shortages in the Â construction of UK housing.
The variety of systems now available potentially allows the Â designer enough choice to sidestep problems deriving Â from constraints posed by the use of any one method. Â MMC systems, from closed-panel timber framed Â systems to bathroom pods are a palette from which Â designers can make choices. They are not necessarily Â stand-alone solutions that anticipate all the needs of Â an individual site and can be mixed and matched Â as appropriate.
These limitations are not obstacles to achieving the good design in MMC-based schemes, but may hinder Â the incorporation of more complex and innovative Â types of MMC from which greater overall benefits Â may be obtained Â which Â are considered under the Â following headings:
1. COST UNCERTAINTY
There is no doubt that, given products of comparable Â performance the key issue in purchases of MMC construction Â systems is the price. At present not enough is known Â about the potential costs of using volumetric and Â closed panel systems to enable confident specification Â at an early date. This inhibits designers from exploring Â the full potential of MMC systems. This is particularly true of the less repetitive, Â small, one-off scheme, where a smaller margin Â of benefits is gained from using MMC. The principal Â barrier to the uptake of MMC, therefore, seems Â to be the perception of cost uncertainty with respect to using more complex systems. Â Without doing substantial project-specific research, Â consultants and their clients simply do not know with Â enough degree of certainty how much the volumetric or Â closed panel systems are likely to cost, and what Â would be the savings to overall project costs produced Â by potential speed gains to offset against increased Â capital expenditure.
This is due to the complexity of assessing the ratio of Â cost of repetitive elements where pricing is relatively Â straightforward to the cost of adjusting elements or Â building in another method for the abnormal condition. Â Decisions to use innovative systems are likely to be Â made once designs are well progressed to enable Â teams to be more certain of costs. This can increase Â the potential for change or result in design compromise Â as the designer attempts to incorporate the specific Â limitations of a particular system in their design.
In an attempt to improve this situation, the MMC consultant and or clients Â could Â pull together a Â directory of MMC Â expanded to include cost comparison data. The huge Â range of variables involved inevitably makes this Â difficult, but a database of current construction cost Â information Â would be an Â invaluable resource.
2. PLANNING PROCESS AND EARLY COMMITMENT Â TO A SYSTEM
The time it can take to obtain planning permission has Â obvious implications both for project cost but also, in Â some circumstances, for architectural Â design innovation.
Most of the more complex types of MMC have an Â impact on dimensioning, the choice of external finish Â and detailing may have some effect on the buildings Â mass. Therefore, Â the construction system should be Â chosen prior to a planning application to avoid Â abortive work, redesign or amendment, or even Â resubmission for planning permission.
However, Â developers Â whose money is at risk, frequently hold Â off deciding on the construction technique until the last Â practicable moment, in order to get any advantage from Â fluctuations in material or component pricing.
Given the potential for lengthy duration of planning Â applications, this means that there is little incentive to Â prepare initial designs for planning with a prior decision Â to incorporate MMC firmly embedded. In cases where Â the developer has a financial or business link with the Â supplier, this is less likely to be the case. As the majority Â of commercial or Â residential developments involve some kind of arrangement with a developer, agreement on construction systems is often left to the stage after planning.
3. TIME INVESTMENT
Another very significant factor is the time investment required at Â the early stages of projects. This is needed to develop the design when the project is still at risk. There is a Â direct relationship between the scale and complexity of Â MMC component and the amount of time required to Â develop a design at an early stage.
The introduction of advanced or complex MMC Â techniques into the design process is potentially costly Â to the design team. A significant amount of research is Â needed to explore alternative systems, to obtain Â verification of suppliersâ€™ Â credentials, investigate Â mortgage and insurance issues, visit previous sites, Â talk to system suppliers, obtain technical performance Â guidelines, understand junctions and interfaces, coordinate Â other consultants, obtain building control input Â and so on.
For a consultant, the only way of investing in this Â research is either through timely payment of increased Â fees by a visionary understanding client or through the anticipation of increased future productivity through repetition when a Â project is phased, or large enough, or likely to be Â followed by another similar project.
The potential of learning a system and then being able Â to repeat lessons learned efficiently is a powerful Â incentive for both client and consultant. By contrast, HTAâ€™ s project at Basingstoke is an example Â of a phased project with a three to four-year duration allowed the design team to repeat Â various elements of the design, and the manufacturer to Â develop improved solutions to technical and supply Â problems.
4. INSUFFICIENT COMMUNICATION
Improved dialogue at the outset of the Â project is Â vital if design quality is to be Â maximised. Constraints and opportunities implicit within Â a particular system are more easily incorporated into Â design if partners communicate pre-planning. Â Increased early communication can be fostered through Â improved long-term partnering relationships.
Clients Â should also partner with a range of suppliers and Â architects so that choice and flexibility is not restricted.
Generally, the inexperienced client or design team will Â have to do more research, with the result Â that there is likely to be significant design development Â without a specific system being incorporated.
This is a Â disincentive to using a more complex system involving a Â higher proportion of MMC, where early decision making Â and knowledge of a systemâ€™ s capabilities have a decisive influence on the nature of the architecture. Â However, Â encouraging the take up Â of MMC through the use of a dedicated funding mechanism may Â assist clients Â in Â finding time for Â research into suitable MMC techniques.
6. SUPPLIERâ€™S ROLE
Site capacity Â studies and early stage pre-planning design studies Â could be undertaken directly by system suppliers Â on behalf of clients, cutting out the usual procedure Â of commissioning design work by independent Â consultants.
There are a Â number of assumptions that Â are generally held about certain types of MMC that may Â have been valid at one time but are no longer true today. Â There is a need for reliable and up to date information Â comparing system criteria, performance data, timescales, lead in times, capacity, construction time, Â sequencing issues, limitations, and benefits.
Therefore Â it would be helpful if a forum Â for discussion and experience exchange was set up.
8. DEMONSTRATING THE BENEFITS OF MMC
There is still a large amount of skepticism about the Â need to go very far down the line with MMC. This is Â reflected in the acceptance of the desirability of Â maintaining or indeed enhancing the pool of traditional Â craft skills throughout the UK.
A balanced view is that there is a demonstrable need Â for the wider use of MMC which is recognized by both Â industry and government. Â The best way for clients Â and the public generally to Â become more confident and knowledgeable about the Â quality of design achievable through MMC is to see it Â demonstrated.
9. FINANCIAL INCENTIVES
There is no doubt that spreading the burden of Â investment through the life of a project helps to ensure Â a higher standard of specification and hence quality. In Â the Netherlands, a â€˜ Green Financingâ€™ Â system has been Â developed by the Dutch government that provides Â favorable loan finance when certain sustainable Â standards are reached. In the UK, the Gallions HA Â has Â pioneered Â a study of this, based on a scheme in Â Thamesmead, â€˜ the Ecopark projectâ€™.